Glass vs Plastic: The Facts

If you do your own grocery shopping, you’ve probably noticed that most food packaging is plastic. There are plastic jars that hold peanut butter, plastic tubes of tomato paste, plastic squeeze bottles of ketchup, plastic bottles of soda, and plastic pouches to hold single- and bulk-serving sizes of just about any other food. Even the raw vegetables and fruits from the produce section usually end up wrapped in a plastic bag to protect them until they make it to the refrigerator.

But just twenty or thirty years ago, the packaging scene looked a little different.

Sodas and juices were sold in glass bottles. Glass jars held baby food, jams, and nut butters. There were monetary incentives to return glass bottles as well. And after paying customers for returning bottles, store owners used to wash and refill them to be resold instead of buying all new containers.

Glass as a packaging material is, in many ways, a sensible choice. It is 100% recyclable, and can be recycled indefinitely without losing quality. 80% of glass packaging today is recycled, with some containers making it back on shelves in a new form in as little as 30 days. Glass also is an inert material, meaning it doesn’t interact with whatever is inside the container. This makes it an ideal beverage and food container as it will preserve taste and not leach harmful chemicals into the food (like almost all plastic does).

On the flip side, plastic can only be recycled a few times before it is no longer useable, and then it is usually fashioned into clothes that typically end up in landfills. Even if plastic bottles are recycled, they are still on the fast track to polluting our planet. Furthermore, plastic bottles are porous and over time change the flavor of the beverage or food item inside them. If exposed to high temperatures, even safe plastics like PET can leach antimony into their contents.

When presented with this information, you might assume that glass is obviously the more sustainable option when choosing what type of package to use for a product. However, there are disadvantages to using glass as well.

Glass is 7 times heavier than plastic at the same volume, making it more costly to transport and fossil fuel intensive to move to its final location. Glass also uses more natural resources during production than plastic does despite glass being manufactured from a more renewable resource than plastic.

Additionally, glass is more prone to shattering than plastic, and it is very dangerous to clean up compared to a flexible plastic pouch. Glass jars can also shatter if the ambient temperature changes too much. Interestingly enough, because glass is so brittle and inert, it requires that glass packaging has a separate lid to seal it. Because plastic can be thermo-sealed, it doesn’t need to have a lid to seal its contents inside. Pouch packaging creates flexible, safe packaging that is light and easy to seal. Pouches also use much less material. For more information on flexible pouch packaging, please see this previous article.

Knowing all this information – plastics are light and flexible, but usually end up in landfills, while glass can waste fossil fuels in production and transportation, but preserve the taste of the contents indefinitely – doesn’t answer the question of whether we should use plastic packaging like we have been, or transition back to glass packaging.

Ultimately this question must be posed for each different packaging type and use. Companies should analyze the pros and cons of each type of packaging and decide for themselves if they should switch back to glass or entertain a third option. In some cases the weight difference may be negligible, and in some cases the taste of the product is more important than the cost to ship it.

This decision considers a lot of different factors and EcoImpact-COMPASS, a software that can compare and prioritize all of these attributes side by side, can help companies decide what package to implement. If your company is looking to make informed packaging decisions and reduce environmental impact, then EcoImpact can streamline this process for you.

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